Biggest botch job I was ever involved in was on a 12000 horsepower, twin turbocharged, two stroke marine diesel main propulsion plant.....
Was sold to Chinese registry and contracted to be complete with a spare piston, piston crown, con rod, bottom end with hand cut white metal bearings, complete with a refurbed cylinder head, valve gear and fuel pump (all singular, by the way)
Looks kinda like this....
http://people.bath.ac.uk/ccsshb/12cyl/Stopped the boat in mid-oggin and stripped out a perfectly servicable complete single cylinder engine unit and replaced it with cracked/broken/corroded parts. Restarted the job, cleaned up all the bits that had been removed and chugged into port. Completed the hand over and flew home alongwith a number of shipmates....
oh - and changed over a fair number of the brass name tags on all the valve handwheels throughout the engineroom so the valve labelled, say, fresh water inlet tank one was actually the suction from number 3 topside fuel tank....
Oh, how we laughed....

Must have taken the poor foreign flag buggers ages to suss it all out........